Genetic dissection of drought tolerance in chickpea (Cicer arietinum L.)

Rajeev K. Varshney 0 1 3 4 5 6 7 8 9 10 Mahendar Thudi 0 1 3 4 5 6 7 8 9 10 Spurthi N. Nayak 0 1 3 4 5 6 7 8 9 10 Pooran M. Gaur 0 1 3 4 5 6 7 8 9 10 Junichi Kashiwagi 0 1 3 4 5 6 7 8 9 10 Lakshmanan Krishnamurthy 0 1 3 4 5 6 7 8 9 10 Deepa Jaganathan 0 1 3 4 5 6 7 8 9 10 Jahnavi Koppolu 0 1 3 4 5 6 7 8 9 10 Abhishek Bohra 0 1 3 4 5 6 7 8 9 10 Shailesh Tripathi 0 1 3 4 5 6 7 8 9 10 Abhishek Rathore 0 1 3 4 5 6 7 8 9 10 Aravind K. Jukanti 0 1 3 4 5 6 7 8 9 10 Veera Jayalakshmi 0 1 3 4 5 6 7 8 9 10 Anilkumar Vemula 0 1 3 4 5 6 7 8 9 10 S. J. Singh 0 1 3 4 5 6 7 8 9 10 Mohammad Yasin 0 1 3 4 5 6 7 8 9 10 M. S. Sheshshayee 0 1 3 4 5 6 7 8 9 10 K. P. Viswanatha 0 1 3 4 5 6 7 8 9 10 0 r. K. Varshney CGIAr Generation Challenge Programme , c/o CIMMYT, Mexico , DF, Mexico 1 Communicated by A. e. Melchinger 2 ) M. Thudi S. n. nayak P. M. Gaur l. Krishnamurthy D. Jaganathan J. Koppolu A. Bohra S. Tripathi A. rathore A. K. Jukanti A. Vemula International Crops research Institute for the Semi-Arid Tropics (ICrISAT) , Hyderabad, India 3 Present Address: A. K. Jukanti Central Arid Zone research Institute (CAZrI) , Jodhpur, India 4 Present Address: S. Tripathi Indian Agricultural research Institute (IArI) , new Delhi, India 5 Present Address: A. Bohra Indian Institute of Pulses research (IIPr) , Kanpur, India 6 Present Address: J. Koppolu leibniz Institute of Plant Genetics and Crop Plant research (IPK) , Gatersleben, Germany 7 J. Kashiwagi Hokkaido University , Sapporo, Japan 8 Present Address: S. n. nayak University of Florida , Florida, USA 9 M. S. Sheshshayee K. P. Viswanatha University of Agricultural Sciences - Bangalore , Bangalore, India 10 M. Yasin rAK College of Agriculture , Sehore, India Chickpea (Cicer arietinum l.) is the second most important grain legume cultivated by resource poor farmers in the arid and semi-arid regions of the world. Drought is one of the major constraints leading up to 50 % production losses in chickpea. In order to dissect the complex nature of drought tolerance and to use genomics tools for enhancing yield of chickpea under drought conditions, two mapping populationsICCrIl03 (ICC 4958 ICC 1882) and ICCrIl04 (ICC 283 ICC 8261) segregating for drought tolerance-related root traits were phenotyped for a total of 20 drought component traits in 1-7 seasons at 1-5 locations in India. Individual genetic maps comprising 241 loci and 168 loci for ICCrIl03 and ICCrIl04, respectively, and a consensus genetic map comprising 352 loci were constructed (http://cmap.icrisat.ac.in/cmap/sm/ cp/varshney/). Analysis of extensive genotypic and precise phenotypic data revealed 45 robust main-effect QTls (M-QTls) explaining up to 58.20 % phenotypic variation and 973 epistatic QTls (e-QTls) explaining up to 92.19 % phenotypic variation for several target traits. nine QTl clusters containing QTls for several drought tolerance traits have been identified that can be targeted for molecular breeding. Among these clusters, one cluster harboring 48 % robust M-QTls for 12 traits and explaining about 58.20 % phenotypic variation present on CalG04 has been referred as QTL-hotspot. This genomic region contains seven SSr markers (ICCM0249, nCPGr127, TAA170, - nCPGr21, Tr11, GA24 and STMS11). Introgression of this region into elite cultivars is expected to enhance drought tolerance in chickpea. Climate change is a global phenomenon that has started to have adverse impact on agriculture. The global temperature is predicted to rise by 2.5 to 4.3 C by the end of the century (IPCC 2007). The situation is further likely to be exacerbated by the occurrence of increase in the irregularity of rainfall, drought, flood and land degradation. Higher temperatures, more hot days and heat waves are very likely to hit over nearly all land areas. In this context, drought remains as a big challenge while addressing the problem of food insecurity, hunger and malnutrition especially in the areas where people mainly depend on subsistence farming as a major source of their livelihood (Tuberosa 2012). Chickpea (Cicer arietinum l.) is grown on low input marginal lands and represents an important component of the subsistence farming. It is the second most important grain legume globally cultivated on an area of 13.20 million hectare (Mha) with an annual production of 11.62 million tons (Mt; FAOSTAT 2011). The global demand for chickpea in 2020 is projected to be 17.0 Mt (up from the current 8.6 Mt; Abate et al. 2012). It is mostly grown on residual moisture from monsoon rains on the Indian subcontinent and semi-arid regions of Sub-Saharan Africa (SSA). India is the largest producer and consumer of chickpea. Among various kinds of abiotic (salinity, heat) stresses affecting the chickpea production, drought stress particularly at the end of the growing season is a major constraint to chickpea production and yield stability in arid and semiarid regions of the world (see Krishnamurthy et al. 2010). Drought causes substantial annual yield losses up to 50 % in chickpea and the productivity remained constant for the past six decades (Ahmad et al. 2005; see Varshney et al. 2010). With predicted climate change scenarios and continuous population explosion, there is a great need to develop high-yielding chickpea varieties with improved drought tolerance (Krishnamurthy et al. 2013a). Drought tolerance is a generic term for a highly complex phenomenon of plant responses. In a practical sense, it is the relative ability of the crop to sustain adequate biomass production and maximize crop yield under increasing water deficit throughout the growing season, rather than the physiological aptitude of the plant for its survival (Serraj and Sinclair 2002). In such context, tolerance to drought is a complex trait with quantitative nature and the underlying mechanism may be due to drought escape, avoidance and tolerance in many crops. Chickpea yields are highly prone to large genotype by environment (G E) interactions in marginal environments (Kashiwagi et al. 2008). Breeding for yield under drought conditions using conventional approaches has not been quite successful over the years due to this instability and the poor heritability. Under such circumstances, molecular breeding seems to be a better strategy that can be deployed by targeting drought tolerance component traits with the help of molecular markers. Understanding genetic basis and identification of molecular markers for drought tolerance component traits are prerequisites for deploying molecular breeding for developing superior genotypes of chickpea. Very recently, significant progress has been made in developing molecular markers and genetic maps in chickpea (nayak et al. 2010; Gujaria et al. 2011; Gaur et al. 2011; Thudi et al. 2011; Hiremath et al. 2012). While several mapping studies have targeted biotic stress tolerance loci (see Milln et al. 2006), drought tolerance trait has not yet been targeted systematically for molecular mapping in c (...truncated)